<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
	*{
		padding: 0;
		margin: 0;
	}
	.menu{
		width: 200px;
		height: 40px;
		border: 3px solid blue;
	}
	.top{
		display: block;
		width: 200px;
		height: 40px;
		background: green;
		color: white;
		text-align: center;
		line-height: 40px;
		font-size: 20px;
		text-decoration: none;
	}
	.list{
		width: 200px;
		background: yellow;
		display: none;
	}
</style>
<script type="text/javascript" src="jquery-1.7.2.min.js"></script>
<script type="text/javascript">
	
$(function(){
	
	$('.menu').mouseover(function() {
		$(this).find('.list').show();
	});

	$('.menu').mouseout(function() {
		$(this).find('.list').hide();
	});


})

</script>
</head>

<body>

<div class="menu">
	<a href="" class="top">客户服务</a>
	<ul class="list">
		<li>后盾网</li>
		<li>后盾网</li>
		<li>后盾网</li>
		<li>后盾网</li>
	</ul>
</div>


</body>
</html>
